Stabilization of silver halide emulsions with 1,1 bis-sulfonyl alkanes

ABSTRACT

Silver halide emulsions and photographic elements containing a 1,1 bis-sulfonyl alkane stabilizing agent are stabilized after exposure by an alkaline activation treatment.

United States Patent Haist et al.

[ Mar. 7, 1972 STABILIZATION OF SILVER I-IALIDE EMULSIONS WITH 1,1BIS-SULFONYL ALKANES Inventors: Grant M. Heist, Rochester; James R.

King, Webster; David A. Pupo Churchville, all of N.Y.

Assignee: Eastman Kodak Company, Rochester,

Filed: June 1, 1970 Appl.No.: 42,580

US. Cl ..96/61, 96/ 109 int. Cl. ...G03c 5/38, G03c l/34 Field of Search..96/ 109, 61

Primary Examiner-Norman G. Torchin Assistant Examiner-Richard E. FichterAttorney-W. H. J. Kline, J. R. Frederick and H. E. Cole [57] ABSTRACTSilver halide emulsions and photographic elements containing a 1,1bis-sulfonyl alkane stabilizing agent are stabilized after exposure byan alkaline activation treatment.

20 Claims, No Drawings STABILIZATION OF SILVER HALIDE EMULSIONS WITH 1,]BIS-SULFONYL ALKANES This invention relates to the art of photography.More particularly, this invention relates to stabilization ofphotographic silver halide emulsions and elements with novel stabilizingagents, obviating the necessity of conventional fixing.

After a photographic silver halide emulsion is developed and a silverimage is produced in the areas of exposure, the silver halide in theunexposed areas is conventionally washed out as a soluble complex with afixing solution. It would be convenient to have the fixing agentincorporated directly in the emulsion.

The suitability of a fixing agent for incorporation in an emulsiondepends on many factors, but it has been difficult to find compoundswhich are satisfactory because of the sensitive nature of the element.Most active fixing agents such as hypo, for example, cannot beincorporated into the light-sensitive element because of the prefixingwhich takes place, that is, the compound reacts to fix the silver halideprematurely and light sensitivity is lost. Other less active fixingcompounds may show such inactivation (prestabilization) on long-termkeeping, so that light sensitivity is lost after a period of time. Otherstill less active fixing agents, while they do not react prematurely,may act with only insufficient completeness so that they do not do asatisfactory fixing job. This results in subsequent background printupand instability in the processed image. Still other known fixing agentscannot be incorporated in light-sensitive coatings because of solubilityrelationships or because of interaction with other components of thesystem. It would be highly desirable to havea fixing agent which couldbe satisfactorily incorporated into a light-sensitive coating and whichwould not interfere with sensitometric properties so that stablecoatings could be made.

It is an object of this invention to provide novel stabilizing agentsfor silver halide emulsions and photographic elements.

It is also an object of this invention to provide a process forstabilizing photographic elements having novel stabilizing agentsincorporated therein by a simple alkaline activation step.

These and other objects of this invention are accomplished byincorporating in a photographic silver halide emulsion or in a layer ofa photosensitive element a 1,1 bis-sulfonyl alkane. It

has been found that the fl-disulfones used in the present invention donot desensitize the emulsion or stabilize the emulsion prior todevelopment. By means of a simple alkaline activation step, thedisulfones then act as effective stabilizers.

The fl-disulfones and their chemical reactions have been described inthe literature. For example, the preparation of these compounds andreactions in which they are involved is described in Suter, OrganicChemistry of Sulfur, on pages 735 and 739. However, it has now beendiscovered that particular B-disulfones, namely, 1,] bis-sulfonylalkanes, are excellent stabilizers when incorporated in photographicsilver halide emulsions or in a layer of a photosensitive element.

Suitable l,1 bis-sulfonyl alkanes used in the present invention can berepresented by the general formula Rr-S Or-CH-S Or -R2 wherein R and Reach represent a lower alkyl group and R represents H or a lower alkylgroup. The term lower alkyl as employed herein is preferably an alkylgroup containing from about one to four carbon atoms, e.g., methyl,ethyl, propyl, isopropyl, butyl and the like. The term alkyl" asemployed herein also includes substituted alkyl groups, and ispreferably a substituted lower alkyl group containing from one to fourcarbon atoms. Thus, substituted lower alkyl groups such as ahydroxyalkyl group, e.g., B-hydroxyethyl, mhydroxybutyl, etc.; analkoxyalkyl group, e.g., B-methoxyethyl, w-butoxybutyl, etc.; acarboxyalkyl group, e.g., B-carboxyethyl, m-carboxybutyl, etc.; asulfoalkyl group, e.g., B-sulfoethyl, w-sulfobutyl, etc.; a sulfatoalkylgroup, e.g., B-sulfatoethyl, w-sulfatobutyl,

include etc.; an acryloxyalkyl group, e.g., fl-acetoxyethyl.w-butyryloxybutyl, etc.; an alkoxycarbonylalkyl group, e.g., B-methoxycarbonyl-ethyl, w-ethoxycarbonylbutyl, etc, are preferred.

l,l Bis-sulfonyl alkanes within the above formula include 1,1bis-(methylsulfonyl)ethane; l,l bis-(ethylsulfonyl)ethane; l,lbis-(methylsulfonyl) propane; 1,1 bis-(ethylsulfonyl)propane;l-ethylsulfonyl-l-methylsulfonyl methane;lethylsulfonyl-l-methylsulfonyl ethane; etc. Especially preferred l,lbis-sulfonyl alkanes are bis(methylsulfonyl)methane, bis(ethylsulfonyl)methane, bis(/3'hydroxyethylsulfonyl)methane,bis(carboxymethylsulfonyl)methane, andbis(B-carboxyethylsulfonyl)methane.

When the novel disulfone stabilizers described herein are incorporatedin a silver halide emulsion, or contiguous to the silver halide, theyserve as incorporated fixing agents. These addenda do not preventdevelopment of exposed areas of the emulsion but protect the unexposedareas of the emulsion against printout after development of theemulsion. Thus, with emulsions containing the addenda of the invention,silver images can be formed and stabilized without the use of aconventional fixing process. The subject addenda are stable and do notact as fixing agents in acidic or neutral media such as in emulsions.However, under aqueous alkaline conditions which usually occurs duringdevelopment, the subject addenda become active fixing agents. If thedeveloping solution is not sufficiently alkaline to activate thedisulfones of the invention at the rate desired, the developed elementcan thereafter be immersed in a stronger alkaline bath for fixing.

The concentration of the novel disulfone stabilizers described hereinwhich may be incorporated into photosensitive elements should besufficient to stabilize all undeveloped silver halide and is usually atleast about one mole of stabilizer per mole of silver halide in thesilver halide emulsion or photosensitive element, preferably about 2 toabout 10 moles of stabilizer per mole of silver halide depending uponthe solubility of the particular agent employed.

A photosensitive element according to the invention comprises a supporthaving thereon a photographic silver halide emulsion layer, the elementcontaining either in the emulsion layer or in a separate layer,preferably contiguous to the emulsion layer, at least one mole per moleof silver halide of the novel disulfone stabilizing agents describedherein. When it is desired to stabilize such element, it is exposed,developed and then treated in an aqueous alkaline medium to form acomplex of unexposed and undeveloped silver halide with the stabilizingagent, thus providing a stable image. If desired, the developing step,as such, can be omitted by incorporating a developing agent directlyinto the photographic element or silver halide emulsion. The alkalinetreatment thus serves to initiate development and then complexing of theunexposed and undeveloped silver halide with the stabilizing agent toprovide a stable image.

Suitable developing agents useful in the present inventionhydroquinones, catechols, aminophenols, 3- pyrazolidones, ascorbic acidand its derivatives, reductones, phenylenediamines, combinationsthereof, etc. The amount of developer to be employed can be varied overa wide range as is well known to those skilled in the art, dependingupon the particular developer employed, its location in the system, etc.

When incorporated in silver halide emulsions or photographic elements asdescribed herein, the novel disulfones of the invention are relativelyinert at pHs below about 8 or 9 and can be coated at that pH or below.However, alkaline activation at pH s at about l0 or above renders thesedisulfones very effective stabilizers.

While it is not necessary to have an auxiliary developing agent presentin the photographic element of the invention, such auxiliary developingagent can be employed, if desired, to improve maximum density of thedeveloped image.

The silver halide emulsions which can be employed with this inventioncan be silver chloride, silver bromide, silver bromoiodide, silverchlorobromoiodide or mixtures thereof.

The emulsions can be coarse or fine-grain and can be prepared by any ofthe well-known procedures in emulsion making such as single-jetemulsions, double-jet emulsions, such as Lippman, ammoniacal emulsions,thiocyanate or thioether ripened emulsions, such as those described inU.S. Pat. No. 2,222,264 of Nietz et al. issued Nov. 19, 1940; U.S. Pat.No. 3,320,069 of lllingsworth issued May 15, 1967; and U.S. Pat. No.3,271,157 of McBride issued Sept. 6, 1966. Surface image emulsions canbe used or internal image emulsions can be used such as those describedin U.S. Pat. No. 2,592,250 of Davey et al. issued Apr. 8, 1952; U.S.Pat. No. 3,206,313 of Porter et a1. issued Sept. 14, 1965; and BelgianPat. No. 704,255. The emulsions can be regular grain emulsions such asthose described in Klein and Moisar, Journal of Photographic Science,Volume 12, No. 5, September-October (1964 pages 242-251. If desired,mixtures of surface and internal image emulsions can be used asdescribed in U.S. Pat. 'No. 2,996,382 of Luckey et al. issued Aug. 15,1961. Negativetype emulsions can be used or direct positive emulsionscan be used such as those described in U.S. Pat. No. 2,184,013 ofLeermakers issued Dec. 19, 1939; U.S. Pat. No. 2,541,472 of Kendall etal. issued Feb. 13, 1951; U.S. Pat. No. 3,367,778 of Berriman et al.issued Feb. 6, 1968; British Pat. 723,019; French Pat. No. 1,520,821;U.S. Pat. No. 2,563,785 of lves issued Aug. 7, 1951; U.S. Pat. No.2,456,953 of Knott et al. issued Dec. 21, 1968; and U.S. Pat. No.2,861,885 of Land issued Nov.25, 1958.

The silver halide emulsions employed in the practice of the inventioncan be unwashed or washed to remove soluble salts. In the latter casethe soluble salts can be removed by chillsetting and leaching or theemulsion can be coagulation washed.

The silver halide emulsions employed in the practice of the inventioncan be sensitized with chemical sensitizers, such as with reducingagents; sulfur, selenium or tellurium compounds; gold, platinum orpalladium compounds; or combinations of these. Suitable procedures aredescribed, for example, in U.S. Pat. No. 1,623,499 of Sheppard issuedApr. 5, 1927; U.S. Pat. No. 2,399,083 of Waller et al. issued Apr. 23,1946; U.S. Pat. No. 3,297,447 of McVeigh issued Jan. 10, 1967 andU.S..Pat. No. 3,297,446 of Dunn issued Jan. 10, 1967.

lfdesired in preparing a photographic silver halide emulsion, spectralsensitizers can be added to the emulsion before a chemical sensitizer isadded. This can result in a speed increase as compared to an emulsionwherein the chemical sensitizer is added before the spectral sensitizer.For example, the silver halide emulsion can be spectrally sensitizedwith anhydro-S,5'-dichloro3,9-diethyl-3'-(3-sulfobutyl) thiacarbocyaninehydroxide; 5-[di-( l-ethyl-2( ll-l)-%-naphthothiazolylidene)iso-propylidene]-1,3-di-(B-methoxyethyl) barbituric acid;anhydro'S,5-dichloro-9-ethyl-3,3 -di( 3-sulfopropyl) oxacarbocyaninehydroxide, sodium salt; or anhydro5,5,6,6'- tetrachloro-1,l-diethyl-3,3'-di(3-sulfobutyl) benzimidazolocarbocyanine hydroxide andthen chemically sensitized with sulfur and gold sensitizers, or sulfur,gold and selenium sensitizers, as described. Heat treatment can becarried out after the spectral sensitizer is added.

Cationic hydroxyalkyl surfactants, such as quaternary salts, whichcontain an omega-hydroxyalkyl group can be employed as chemicalsensitizers for silver halides, e.g., a silver halide dispersed ingelatin or synthetic polymeric vehicles. Compounds which are cationicsurfactant sulfonium compound chemical sensitizers are set out in U.S.Pat. No. 2,271,623 and U.S. Pat. No. 2,275,727 as well as variousquaternary ammonium compounds. Tetraalkyl quaternary ammonium salts,pyridinium quaternary salts, piperidinium salts, pyrazolium quaternarysalts, and quinolinium salts which contain an omega-hydroxyalkyl groupare suitable compounds which can be employed to increase thephotographic speed of silver halide.

The silver halide emulsions employed in the practice of the inventioncan contain speed increasing compounds such as polyalkylene glycols,cationic surfactants and thioethers or combinations of these asdescribed, for example, in U.S. Pat. No. 2,886,437 of Piper issued May12, 1959; U.S. Pat. No. 3,046,134 of Dann et al. issued July 24, 1962;U.S. Pat. No. 2,944,900 of Carroll et al. issued July 12, 1960; and U.S.Pat. No. 3,294,540 ofGoffe issued Dec. 27, 1966.

The described silver halide emulsions employed in the practice of theinvention can be protected against the production of fog and can bestabilized against loss of sensitivity during keeping. Suitableantifoggants and stabilizers each used alone or in combination include,for example, thiazolium salts; azaindenes; mercury salts as described,for example, in U.S. Pat. No. 2,728,663 of Allen et al. issued Dec. 27,1955; urazoles; sulfocatechols; oximes described, for example, inBritish Pat. No. 623,448; nitron; nitroindazoles; mercaptotetrazoles;polyvalent metal salts described, for example, in

U.S. Pat. No. 2,839,405 of Jones issued June 17, 1958; palladium,platinum and gold salts described, for example, in U.S. Pat. No.2,566,263 ofTrevelli et al. issued Aug. 28, 1951 and U.S. Pat. No.2,597,915 of Yutzy et al. issued May 27, 1952.

The photographic and other hardenable layers of a photographic elementused in the practice of the invention can be hardened by various organicor inorganic hardeners alone or in combination, such as aldehydehardeners and blocked a1- dehydes, ketones, carboxylic and carbonic acidderivatives, sulfonate esters, sulfonyl halides and vinyl sulfones,active halogen compounds, epoxy compounds, azirindenes, active olefins,isocyanates, carbodiimides, mixed-function hardeners and polymerichardeners such as oxidized polysaccharides such as dialdehyde starch andoxyguargum and the like.

A photographic element and emulsions described in the practice of theinvention can contain various colloids alone or in combination asvehicles, binding agents and in various layers. Suitable hydrophilicmaterials include those naturally occurring substances such as proteins,for example, gelatin, gelatin derivatives, cellulose derivatives,polysaccharides such as dextran, gum arabic and the like; and syntheticpolymeric substances such as water-soluble polyvinyl compounds likepoly(vinylpyrrolidone), acrylamide polymers and the like.

The described photographic emulsion layers and other layers of thephotographic element employed in the practice of the invention can alsocontain, alone or in combination with hydrophilic, water-permeablecolloids, other synthetic polymeric compounds such as dispersed vinylcompounds, such as in latex form, and particularly those whichincreasethe dimensional stability of the photographic materials. Suitablesynthetic polymers include those described in U.S. Pat. No. 3,142,586 ofNottorf issued July 28, 1964; U.S. Pat. No.

3,193,386 of White issued July 6, 1965; U.S. Pat. No.

3,062,674 of Houck et al.-issued Nov. 6, 1962; U.S. Pat. No. 3,220,844of Houcket al. issued Nov. 30, 1965; U.S. Pat. No. 3,287,289 of Ream etal. issued Nov. 22, 1966; and U.S. Pat. No. 3,411,911 of Dykstra issuedNov. 19, 1968. Particularly effective are those water insoluble polymersof alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylatesor methacrylates, and those which have cross-linking sites whichfacilitate hardening or curing as well as those having recurringsulfobetaine units as described in Canadian Pat. No. 774,054.

The photographic elements employed in the practice of the invention cancontain antistatic or conducting layers. Such layers can comprisesoluble salts such as chloride, nitrate and the like evaporated metallayers, ionic polymers such as those described in U.S. Pat. No.2,861,056 of Minsk issued Nov. 18, 1958 and U.S. Pat. No. 3,206,312 ofSterman et al. issued Sept. 14, 1965 or insoluble organic salts such asthose described in U.S. Pat. No. 3,428,451 of Trevoy issued Feb. 18,1969.

The photographic emulsions and other layers of a photographic elementemployed in the practice of the invention and described herein can becoated on a wide variety of supports. Typical supports include cellulosenitrate film, cellulose acetate film, poly(vinylacetal) film,polystyrene film, poly(ethylene terephthalate) film, polycarbonate filmand related films or resinous materials as well as glass, paper, metaland the like. Typically a flexible support is employed, especially apaper support which can be partially acetylated or coated with barytaand/or an alpha olefin polymer, particularly a polymer of an alphaolefin containing two to carbon atoms such as polyethylene,polypropylene, ethylene-butene copolymers and the like.

Paper supports which can contain acidic materials to control pl-l can beespecially useful. Such paper supports can contain acids such as boricacid and phthalic acids, as described, for example, in U.S. Pat. No.3,250,619 and U.S. Pat. No. 3,326,744.

The photograph elements employed in the practice of the invention cancontain plasticizers and lubricants such as polyalcohols, glycerin anddiols as described, for example, in U.S. Pat. No. 2,960,404 of Milton etal. issued Nov. 1, 1966; fatty acids or esters such as described in U.S.Pat. No. 2,588,765 of Robijns issued Mar. 11, 1952; and U.S. Pat. No.3,121,160 of Duane issued Feb. 11, 1964; and silicone resins such asthose described in British Pat. No. 955,061

The photographic elements employed in the practice of the invention cancontain surfactants such as saponin, anionic compounds, such as alkylaryl sulfonates described, for example, in U.S. Pat. No. 2,600,831 ofBaldsiefen issued June 17, 1952 and amphoteric compounds such as thosedescribed in U.S. Pat. No. 3,133,816 of Ben-Ezra issued May 19, 1964.

The described photographic elements containing an incorporateddeveloping agent can contain an antioxidant such as a water-solublesulfite or bisulfite, e.g., sodium formaldehyde bisulfite,such asdescribed in U.S. Pat. No. 3,212,895 of Barbier et al. and U.S. Pat. No.3,418,132 of Kitze.

The photographic elements employed in the practice of the invention cancontain matting agents such as starch, titanium dioxide, zinc oxide,silica, and polymeric beads including beads described, for example, inU.S. Pat. No. 2,922,101 of .lelley et al. issued July 1 1, 1961 and U.S.Pat. No. 2,701,245 of Lynn issued Feb. 1, 1955.

The described photographic elements employed in the practice of theinvention can also contain a brightening agent including stilbene,triazine, oxazole] and/or coumarin brightening agents. Water-solublebrighteners such as those described in German Pat. No. 972,067 and U.S.Pat. No. 2,933,390 of McFall et al. issued Apr. 19, 1960 or dispersionsof brighteners can be used such as those described in German Pat. No.1,150,274 and U.S. Pat. No. 3,406,070 of Oetiker et al. issued Oct. 15,1968 and French Pat. No. 1,530,244.

The photographic silver halide emulsions employed in the practice of theinvention can be X-ray or other nonspectrally sensitized emulsions orthey can contain spectral sensitizing dyes. The photographic silverhalide emulsions can conveniently be orthosensitized or pansensitizedwith spectral sensitizing dyes. For instance, these emulsions can bespectrally sensitized by treating with a solution of a sensitizing dyein an organic solvent or the dye can be added in the form of adispersion such as described in French Pat. No. 1,482,774. Spectralsensitizing dyes useful in sensitizing such emulsions are described, forexample, in U.S. Pat. No. 2,526,632 of Brooker et al. issued Oct. 24,1950; U.S. Pat. No. 2,503,776 of Sprague issued Apr. 11, 1950; U.S. Pat.No. 2,493,748 of Brooker et al. issued Jan. 10, 1950; and U.S. Pat. No.3,384,486 of Taber et al. issued May 21, 1968. Spectral sensitizerswhich can be used include the cyanines, merocyanines, complex(trinuclear or tetranuclear) cyanines, complex (trinuclear ortetranuclear) merocyanines, holopolar cyanines, styryls, hemicyanines,such as enamine hemicyanines, oxonols and hemioxonols. Dyes of thecyanine classes can contain such basic nuclei as the thiazolines,oxazolines, pyrrolines, pyridines, oxazoles, thiazoles, selenazoles andimidazoles. Such nuclei can contain alkyl, alkylene, hydroxyalkyl,sulfoalkyl, carboxyalkyl, aminoalkyl and enamine groups and can be fusedto carbocyclic or heterocyclic ring systems either unsubstituted orsubstituted with halogen, phenyl, alkyl, haloalkyl, cyano or alkoxygroups. The dyes can be symmetrical or unsymmetrical and can containalkyl, phenyl, enamine or heterocyclic substituents on the methine orpolymethine chain. The merocyanine dyes can contain the basic nucleidescribed as well as acid nuclei such as thiohydantoins, rhodanines,oxazolidenediones, thiazolidenediones, barbituric acids, thiazolinonesand malononit'rileIThese acid nuclei can be substituted with alkyl,alkylene, phenyl, carboxyalkyl, sulfoalkyl, hydroxyalkyl, alkoxyalkyl,alkylamino groups or heterocyclic nuclei. Combinations of these dyes canbe used if desired. In addition, supersensitizing addenda which do notabsorb visible light can be included, such as ascorbic acid derivatives,azaindenes, cadmium salts and organic sulfonic acids as described inU.S. Pat. No. 2,933,390 of McFall et al. issued Apr. 19, 1960 and U.S.Pat. No. 2,937,089 of Jones et al. issued May 17, 1960.

The various layers including the photographic emulsion layer of thephotographic element employed in the practice of the invention cancontain light absorbing materials and filter dyes such as thosedescribed in U.S. Pat. No. 3,253,921 of Sawdey issued May 31, 1966; U.S.Pat. No. 2,274,782 of Gaspar issued Mar. 3, 1942; U.S. Pat. No.2,527,583 of Silberstein et al. issued Oct. 31, 1950; and U.S. Pat. No.2,956,879 of VanCampen issued Oct. 18, 1960. If desired, the dyes can bemordanted, for example, as described in U.S. Pat. No. 3,282,699 of Joneset al. issued Nov. 1, 1966.

The sensitizing dyes and other addenda such as the described silverhalide developing agents and silver halide stabilizer precursors used inthe practice of the invention can be added from water solutions orsuitable organic solvent solutions can be used. The compounds can beadded using various procedures including those described in U.S. Pat.No. 2,912,343 of Collins et al. issued Nov. 10, 1959; U.S. Pat. No.3,342,605 of McCrossen et al. issued Sept. 19, 1967; U.S. Pat. No.2,996,287 of Audran issued Apr. 15, 1961; and U.S. Pat. No. 3,425,835 ofJohnson et al. issued Feb. 4, 1969.

After exposure, the resulting latent image in a photographic elementaccording to the invention can be developed and stabilized by contactingthe element with an alkaline activator. An especially suitable activatoris an aqueous alkaline solution comprising potassium hydroxide at a pHof about 10 to about 14.5, especially 12 to 14.5.

Alkaline activators which can be employed in developing a latent imagein a photographic element as described include any of those whichprovide the desired activation of the described silver halide developingagents and silver halide stabilizer precursors. These include, forinstance, aqueous alkaline activator solutions commonly employed inrapid access processing of photographic elements, such as those employedin so-called reader-printers. Alkaline activators which are suitableinclude inorganic alkali such as alkali metal hydroxides, especiallysodium hydroxide, potassium hydroxide and/or lithium hydroxide, alkalimetal carbonates, such as sodium carbonate and potassium carbonate,sodium or potassium phosphates, and organic alkaline developmentactivators such as quaternary ammonium bases and salts and alkanolaminessuch as ethanol amine, and similar alkaline materials and/or alkalireleasing materials. Such development activators can be applied to thephotographic element employed in the practice of the invention in anysuitable manner, including for example, dipping, spraying and/or surfaceapplications such as with rollers, as described in U.S. Pat. No.3,025,779 of Russell et al. issued Mar. 20, 1962 or by surfaceapplication processing as described in U.S. Pat. No. 3,418,132 of Kitzeissued Dec. 24, 1968.

If desired an alkaline solution can be employed containing conventionalsilver halide developing agents such as those described. So-called webprocessing can be employed as described, for example, in U.S. Pat. No.3,179,517 of Tregillus et al. issued Apr. 20, 1965 or so-calledstabilization processing as described in Russell et al., PSA Journal,Volume 16b, Aug. 1950.

If desired the alkaline activator, especially an aqueous alkalineactivator solution can contain a hardener as described.

The time for processing a photographic element in the practice of theinvention, that is developing and stabilizing a desired latent image,can vary over a wide range, typically between about 1 second to severalminutes depending on the desired image, processing conditions and thelike.

The conditions for processing can also vary, but usually ambientpressures and temperatures of about 20 C. to about 30 C. are employed.If desired, higher temperatures can be used such as temperatures up toabout 90 C.

it can be useful in some cases to wash the resulting photographicelement after processing with water, such as a water rinse, for about 1second to about minutes to remove watersoluble compounds. This canimprove post processing stability and reduce any stain.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1 The following coating composition is prepared and coated at0.004 inch wet thickness on a baryta-coated paper base:

Water 40 ml.

Gelatin, lS-% solution 40 ml. Bistmethylsulfonyhmethune 3 g.l-Phenyl-2-carbohexyloxy-3-pyrazolidone 0.8 g. Hydroquinone 2 g.Negative-type, medium speed, gelatinosilver chloride-gelatin emulsioncontaining 40 mg. silver/ml. 5 ml.

This composition contains approximately 8 moles of the stabilizercompound per mole of silver. After drying, the resulting photographicelement is then exposed to an image and then immersed for 10 seconds ina solution at 75 F. containing 5 percent sodium hydroxide, 5 percentsodium sulfite and 5 percent sodium sulfate. The element is then washedin water. A blue-black image of excellent density and emulsion speed isobtained with a white background that is stable to the continued effectof light.

EXAMPLES 2-4 Example 1 is repeated but with bis(ethylsulfonyl)methane,bis(B-hydroxyethylsulfonyl)methane and bis(carboxymethylsulfonyl)methanein place of the bis(methylsulfonyl)methane. Similar results areobtained.

EXAMPLE 5 A photographic element is prepared according to the procedureof Example I. A portion of the element is incubated for 7 days at 120 F.and 35 percent Relative Humidity. Both portions of the element are thenprocessed as in Example 1. The following sensitometric values areobtained:

Coating Contract D Fresh 0.72 L02 lncu bated 0.74 1.08

This data clearly indicate that there was no prestabilization of thelight-sensitive material since the element retains its ability to befully developed by alkaline activator after a full week at 120 F. and 35percent Relative Humidity.

The invention has been described with particular reference to certainpreferred embodiments thereof, but is will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

We claim:

1. A photographic silver halide emulsion containing at least one moleper mole of silver halide of a l,l bis-sulfonyl alkane stabilizingagent.

2. The photographic emulsion of claim 1 wherein said stabilizing agenthas the formula wherein R, and R each represent an alkyl groupcontaining one to four carbon atoms and R represents H or an alkyl groupcontaining one to four carbon atoms.

3. The photographic emulsion'of claim 2 wherein R, and R each representmethyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethyl groups and Rrepresents H.

4. The photographic emulsion of claim 3 wherein R, and R each representa methyl group.

5. A photosensitive element comprising a support having thereon aphotographic silver halide emulsion layer, said element containing atleast one mole per mole of silver halide of a l,l bis-sulfonyl alkanestabilizing agent.

6. The photosensitive element of claim 5 wherein said stabilizing agenthas the formula Ra Rr-S 0r- JH-s 02-11 wherein R, and R each representan alkyl group containing one to four carbon atoms and R represents H oran alkyl group containing one to four carbon atoms.

7. The photosensitive element of claim 6 wherein R, and R each representmethyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethyl groups and Rrepresents H.

8. The photosensitive element of claim 7 wherein R, and R each representa methyl group.

9. The photosensitive element of claim 5 which includes a photographicsilver halide developing agent incorporated therein.

10. The photosensitive element of claim 9 wherein said stabilizing agenthas the formula wherein R, and R each represent an alkyl groupcontaining one to four carbon atoms and R represents H or an alkyl groupcontaining one to four carbon atoms.

11. The photosensitive element of claim 10 wherein R, and R, eachrepresent methyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethylgroups and R represents H.

12. The photosensitive element of claim 11 wherein R, and R eachrepresent a methyl group.

13. A process for stabilizing a photographic element comprising:

a. exposing a photosensitive element comprising a support having thereona photographic silver halide emulsion layer, said element containing atleast 1 mole per mole of silver halide of a l,l bis-sulfonyl alkanestabilizing agent.

b. developing exposed silver halide of said exposed element,

and

c. complexing resulting unexposed and undeveloped silver halide withsaid stabilizing agent in an aqueous alkaline medium thus providing astable image.

14. The process of claim 13 wherein said stabilizing agent has theformula wherein R, and R each represent an alkyl group containing one tofour carbon atoms and R represents H or an alkyl group containing one tofour carbon atoms.

15. The process of claim 14 wherein R, and R each represent methyl,ethyl, hydroxyethyl, carboxymethyl or carboxyethyl groups and Rrepresents H.

16. The process of claim 15 wherein R, and R eachv represent a methylgroup.

17. A process for stabilizing a photographic element comprising:

9 V 1. a. exposing a photosensitive element comprising a support havingthereon a photographic silver halide emulsion E layer, said elementcontaining at least one mole per mole a. V a r of Silver Palide of a 1,1q y stabilizing wherein R and R each represent an alkyl group containingagent element also a Sllver halide 5 one to four carbon atoms and Rrepresents H or an alkyl developmg agent Incorporated therem and groupcontaining one to four carbon atoms.

b. treating said element in an aqueous alkaline medium to initiatedevelopment of exposed silver halide and then complexing of unexposedand undeveloped silver halide with said stabilizing agent to provide astable image.

18. The process of claim 17 wherein said stabilizing agent has theformula 19. The photographic emulsion of claim 18 wherein R, and R eachrepresent methyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethylgroups and R represents H.

20. The photographic emulsion of claim 19 wherein R, and R eachrepresent a methyl group.

wars smrsrmm OFFICEM W69) CERTIFICATE or CCRRECHCN Patent No. 2.,eLLLL63 Dated March 7. 1972 Inventofls) Grant M. Haist, James King; andDavid A. Pupo It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

In Column 1, line 71, "mhydroxybutyl" should read -hydroXybutyl--.

In Column 2, line 20, "printout" should read --print-out. 4

In Column 3, line 51 "2(lH)7/8" should read ---2(1H)--,9---.

In Column 7, line 26, "0.8 g. should be directly across froml--Phenyl2-carbohexyloXy-3--pyrazolidone' and under "3 g.".

In Column 7, line 56, "Contract should read- ---Contrast-- Signed andsealed this 21st day of November 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GO'ITSCHALK Attesting Ofilcer Commissionerof Patents

2. The photographic emulsion of claim 1 wherein said stabilizing agenthas the formula wherein R1 and R2 each represent an alkyl groupcontaining one to four carbon atoms and R3 represents H or an alkylgroup containing one to four carbon atoms.
 3. The photographic emulsionof claim 2 wherein R1 and R2 each represent methyl, ethyl, hydroxyethyl,carboxymethyl or carboxyethyl groups and R3 represents H.
 4. Thephotographic emulsion of claim 3 wherein R1 and R2 each represent amethyl group.
 5. A photosensitive element comprising a support havingthereon a photographic silver halide emulsion layer, said elementcontaining at least one mole per mole of silver halide of a 1,1bis-sulfonyl alkane stabilizing agent.
 6. The photosensitive element ofclaim 5 wherein said stabilizing agent has the formula wherein R1 and R2each represent an alkyl group containing one to four carbon atoms and R3represents H or an alkyl group containing one to four carbon atoms. 7.The photosensitive element of claim 6 wherein R1 and R2 each representmethyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethyl groups and R3represents H.
 8. The photosensitive element of claim 7 wherein R1 and R2each represent a methyl group.
 9. The photosensitive element of claim 5which includes a photographic silver halide developing agentincorporated therein.
 10. The photosensitive element of claim 9 whereinsaid stabilizing agent has the formula wherein R1 and R2 each representan alkyl group containing one to four carbon atoms and R3 represents Hor an alkyl group containing one to four carbon atoms.
 11. Thephotosensitive element of claim 10 wherein R1 and R2 each representmethyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethyl groups and R3represents H.
 12. The photosensitive element of claim 11 wherein R1 andR2 each represent a methyl group.
 13. A process for stabilizing aphotographic element comprising: a. exposing a photosensitive elementcomprising a support having thereon a photographic silver halideemulsion layer, said element containing at least 1 mole per mole ofsilver halide of a 1,1 bis-sulfonyl alkane stabilizing agent. b.developing exposed silver halide of said exposed element, and c.complexing resulting unexposed and undeveloped silver halide with saidstabilizing agent in an aqueous alkaline medium thus providing a stableimage.
 14. The process of claim 13 wherein said stabilizing agent hasthe formula wherein R1 and R2 each represent an alkyl group containingone to four carbon atoms and R3 represents H or an alkyl groupcontaining one to four carbon atoms.
 15. The process of claim 14 whereinR1 and R2 each represent methyl, ethyl, hydroxyethyl, carboxymethyl orcarboxyethyl groups and R3 represents H.
 16. The process of claim 15wherein R1 and R2 each represent a methyl group.
 17. A process forstabilizing a photographic element comprising: a. exposing aphotosensitive element comprising a support having thereon aphotographic silver halide emulsion layer, said element containing atleast one mole per mole of silver halide of a 1,1 bis-sulfonyl alkanestabilizing agent, said element also containing a silver halidedeveloping agent incorporated therein, and b. treating said element inan aqueous alkaline medium to initiate development of exposed silverhalide and then complexing of unexposed and undeveloped silver halidewith said stabilizing agent to provide a stable image.
 18. The processof claim 17 wherein said stabilizing agent has the formula wherein R1and R2 each represent an alkyl group containing one to four carbon atomsand R3 represents H or an alkyl group containing one to four carbonatoms.
 19. The photographic emulsion of claim 18 wherein R1 and R2 eachrepresent methyl, ethyl, hydroxyethyl, carboxymethyl or carboxyethylgroups and R3 represents H.
 20. The photographic emulsion of claim 19wherein R1 and R2 each represent a methyl group.